2 * Copyright (c) 2003 Marcel Moolenaar
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 #include "opt_comconsole.h"
34 #include <sys/param.h>
35 #include <sys/systm.h>
39 #include <sys/fcntl.h>
40 #include <sys/interrupt.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/queue.h>
45 #include <sys/reboot.h>
46 #include <machine/bus.h>
48 #include <sys/termios.h>
50 #include <machine/resource.h>
51 #include <machine/stdarg.h>
53 #include <dev/uart/uart.h>
54 #include <dev/uart/uart_bus.h>
55 #include <dev/uart/uart_cpu.h>
59 devclass_t uart_devclass;
60 char uart_driver_name[] = "uart";
62 SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs =
63 SLIST_HEAD_INITIALIZER(uart_sysdevs);
65 MALLOC_DEFINE(M_UART, "UART", "UART driver");
68 uart_add_sysdev(struct uart_devinfo *di)
70 SLIST_INSERT_HEAD(&uart_sysdevs, di, next);
74 uart_getname(struct uart_class *uc)
76 return ((uc != NULL) ? uc->name : NULL);
80 uart_getops(struct uart_class *uc)
82 return ((uc != NULL) ? uc->uc_ops : NULL);
86 uart_getrange(struct uart_class *uc)
88 return ((uc != NULL) ? uc->uc_range : 0);
92 * Schedule a soft interrupt. We do this on the 0 to !0 transition
93 * of the TTY pending interrupt status.
96 uart_sched_softih(struct uart_softc *sc, uint32_t ipend)
101 old = sc->sc_ttypend;
103 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
105 if ((old & SER_INT_MASK) == 0)
106 swi_sched(sc->sc_softih, 0);
110 * A break condition has been detected. We treat the break condition as
111 * a special case that should not happen during normal operation. When
112 * the break condition is to be passed to higher levels in the form of
113 * a NUL character, we really want the break to be in the right place in
114 * the input stream. The overhead to achieve that is not in relation to
115 * the exceptional nature of the break condition, so we permit ourselves
119 uart_intr_break(void *arg)
121 struct uart_softc *sc = arg;
123 #if defined(KDB) && defined(BREAK_TO_DEBUGGER)
124 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
125 kdb_enter_why(KDB_WHY_BREAK, "Line break on console");
130 uart_sched_softih(sc, SER_INT_BREAK);
135 * Handle a receiver overrun situation. We lost at least 1 byte in the
136 * input stream and it's our job to contain the situation. We grab as
137 * much of the data we can, but otherwise flush the receiver FIFO to
138 * create some breathing room. The net effect is that we avoid the
139 * overrun condition to happen for the next X characters, where X is
140 * related to the FIFO size at the cost of loosing data right away.
141 * So, instead of having multiple overrun interrupts in close proximity
142 * to each other and possibly pessimizing UART interrupt latency for
143 * other UARTs in a multiport configuration, we create a longer segment
144 * of missing characters by freeing up the FIFO.
145 * Each overrun condition is marked in the input buffer by a token. The
146 * token represents the loss of at least one, but possible more bytes in
150 uart_intr_overrun(void *arg)
152 struct uart_softc *sc = arg;
156 if (uart_rx_put(sc, UART_STAT_OVERRUN))
157 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
158 uart_sched_softih(sc, SER_INT_RXREADY);
160 UART_FLUSH(sc, UART_FLUSH_RECEIVER);
165 * Received data ready.
168 uart_intr_rxready(void *arg)
170 struct uart_softc *sc = arg;
175 #if defined(KDB) && defined(ALT_BREAK_TO_DEBUGGER)
176 if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
177 while (rxp != sc->sc_rxput) {
178 if (kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk))
179 kdb_enter_why(KDB_WHY_BREAK,
180 "Break sequence on console");
181 if (rxp == sc->sc_rxbufsz)
187 uart_sched_softih(sc, SER_INT_RXREADY);
189 sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */
194 * Line or modem status change (OOB signalling).
195 * We pass the signals to the software interrupt handler for further
196 * processing. Note that we merge the delta bits, but set the state
197 * bits. This is to avoid loosing state transitions due to having more
198 * than 1 hardware interrupt between software interrupts.
201 uart_intr_sigchg(void *arg)
203 struct uart_softc *sc = arg;
206 sig = UART_GETSIG(sc);
208 if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) {
209 if (sig & UART_SIG_DPPS) {
210 pps_capture(&sc->sc_pps);
211 pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ?
212 PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
217 * Keep track of signal changes, even when the device is not
218 * opened. This allows us to inform upper layers about a
219 * possible loss of DCD and thus the existence of a (possibly)
220 * different connection when we have DCD back, during the time
221 * that the device was closed.
224 old = sc->sc_ttypend;
225 new = old & ~SER_MASK_STATE;
226 new |= sig & SER_INT_SIGMASK;
227 } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new));
230 uart_sched_softih(sc, SER_INT_SIGCHG);
235 * The transmitter can accept more data.
238 uart_intr_txidle(void *arg)
240 struct uart_softc *sc = arg;
244 uart_sched_softih(sc, SER_INT_TXIDLE);
252 struct uart_softc *sc = arg;
255 while (!sc->sc_leaving && (ipend = UART_IPEND(sc)) != 0) {
257 if (ipend & SER_INT_OVERRUN)
258 uart_intr_overrun(sc);
259 if (ipend & SER_INT_BREAK)
261 if (ipend & SER_INT_RXREADY)
262 uart_intr_rxready(sc);
263 if (ipend & SER_INT_SIGCHG)
264 uart_intr_sigchg(sc);
265 if (ipend & SER_INT_TXIDLE)
266 uart_intr_txidle(sc);
268 return((flag)?FILTER_HANDLED:FILTER_STRAY);
272 uart_bus_ihand(device_t dev, int ipend)
277 return (uart_intr_break);
278 case SER_INT_OVERRUN:
279 return (uart_intr_overrun);
280 case SER_INT_RXREADY:
281 return (uart_intr_rxready);
283 return (uart_intr_sigchg);
285 return (uart_intr_txidle);
291 uart_bus_ipend(device_t dev)
293 struct uart_softc *sc;
295 sc = device_get_softc(dev);
296 return (UART_IPEND(sc));
300 uart_bus_sysdev(device_t dev)
302 struct uart_softc *sc;
304 sc = device_get_softc(dev);
305 return ((sc->sc_sysdev != NULL) ? 1 : 0);
309 uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
311 struct uart_softc *sc;
312 struct uart_devinfo *sysdev;
315 sc = device_get_softc(dev);
318 * All uart_class references are weak. Check that the needed
319 * class has been compiled-in. Fail if not.
321 if (sc->sc_class == NULL)
325 * Initialize the instance. Note that the instance (=softc) does
326 * not necessarily match the hardware specific softc. We can't do
327 * anything about it now, because we may not attach to the device.
328 * Hardware drivers cannot use any of the class specific fields
331 kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class);
333 if (device_get_desc(dev) == NULL)
334 device_set_desc(dev, uart_getname(sc->sc_class));
337 * Allocate the register resource. We assume that all UARTs have
338 * a single register window in either I/O port space or memory
339 * mapped I/O space. Any UART that needs multiple windows will
340 * consequently not be supported by this driver as-is. We try I/O
341 * port space first because that's the common case.
344 sc->sc_rtype = SYS_RES_IOPORT;
345 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
346 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
347 if (sc->sc_rres == NULL) {
349 sc->sc_rtype = SYS_RES_MEMORY;
350 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype,
351 &sc->sc_rrid, 0, ~0, uart_getrange(sc->sc_class),
353 if (sc->sc_rres == NULL)
358 * Fill in the bus access structure and compare this device with
359 * a possible console device and/or a debug port. We set the flags
360 * in the softc so that the hardware dependent probe can adjust
361 * accordingly. In general, you don't want to permanently disrupt
364 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
365 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
366 sc->sc_bas.chan = chan;
367 sc->sc_bas.regshft = regshft;
368 sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
370 SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
371 if (chan == sysdev->bas.chan &&
372 uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
373 /* XXX check if ops matches class. */
374 sc->sc_sysdev = sysdev;
375 sysdev->bas.rclk = sc->sc_bas.rclk;
379 error = UART_PROBE(sc);
380 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
381 return ((error) ? error : BUS_PROBE_DEFAULT);
385 uart_bus_attach(device_t dev)
387 struct uart_softc *sc, *sc0;
392 * The sc_class field defines the type of UART we're going to work
393 * with and thus the size of the softc. Replace the generic softc
394 * with one that matches the UART now that we're certain we handle
397 sc0 = device_get_softc(dev);
398 if (sc0->sc_class->size > sizeof(*sc)) {
399 sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO);
400 bcopy(sc0, sc, sizeof(*sc));
401 device_set_softc(dev, sc);
406 * Protect ourselves against interrupts while we're not completely
407 * finished attaching and initializing. We don't expect interrupts
408 * until after UART_ATTACH() though.
412 mtx_init(&sc->sc_hwmtx_s, "uart_hwmtx", NULL, MTX_SPIN);
413 if (sc->sc_hwmtx == NULL)
414 sc->sc_hwmtx = &sc->sc_hwmtx_s;
417 * Re-allocate. We expect that the softc contains the information
418 * collected by uart_bus_probe() intact.
420 sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype, &sc->sc_rrid,
421 0, ~0, uart_getrange(sc->sc_class), RF_ACTIVE);
422 if (sc->sc_rres == NULL) {
423 mtx_destroy(&sc->sc_hwmtx_s);
426 sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
427 sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
430 sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid,
431 RF_ACTIVE | RF_SHAREABLE);
432 if (sc->sc_ires != NULL) {
433 error = bus_setup_intr(dev,
434 sc->sc_ires, INTR_TYPE_TTY,
435 uart_intr, NULL, sc, &sc->sc_icookie);
437 error = bus_setup_intr(dev,
438 sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE,
439 NULL, (driver_intr_t *)uart_intr, sc, &sc->sc_icookie);
444 device_printf(dev, "could not activate interrupt\n");
445 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
450 if (sc->sc_ires == NULL) {
451 /* XXX no interrupt resource. Force polled mode. */
455 sc->sc_rxbufsz = IBUFSIZ;
456 sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf),
458 sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf),
461 error = UART_ATTACH(sc);
465 if (sc->sc_hwiflow || sc->sc_hwoflow) {
467 device_print_prettyname(dev);
468 if (sc->sc_hwiflow) {
469 printf("%sRTS iflow", sep);
472 if (sc->sc_hwoflow) {
473 printf("%sCTS oflow", sep);
479 if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) {
481 device_print_prettyname(dev);
482 if (sc->sc_fastintr) {
483 printf("%sfast interrupt", sep);
487 printf("%spolled mode", sep);
493 if (sc->sc_sysdev != NULL) {
494 if (sc->sc_sysdev->baudrate == 0) {
495 if (UART_IOCTL(sc, UART_IOCTL_BAUD,
496 (intptr_t)&sc->sc_sysdev->baudrate) != 0)
497 sc->sc_sysdev->baudrate = -1;
499 switch (sc->sc_sysdev->type) {
500 case UART_DEV_CONSOLE:
501 device_printf(dev, "console");
503 case UART_DEV_DBGPORT:
504 device_printf(dev, "debug port");
506 case UART_DEV_KEYBOARD:
507 device_printf(dev, "keyboard");
510 device_printf(dev, "unknown system device");
513 printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate,
514 "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits,
515 sc->sc_sysdev->stopbits);
518 sc->sc_pps.ppscap = PPS_CAPTUREBOTH;
519 pps_init(&sc->sc_pps);
521 error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
522 ? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
526 if (sc->sc_sysdev != NULL)
527 sc->sc_sysdev->hwmtx = sc->sc_hwmtx;
534 free(sc->sc_txbuf, M_UART);
535 free(sc->sc_rxbuf, M_UART);
537 if (sc->sc_ires != NULL) {
538 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
539 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
542 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
544 mtx_destroy(&sc->sc_hwmtx_s);
550 uart_bus_detach(device_t dev)
552 struct uart_softc *sc;
554 sc = device_get_softc(dev);
558 if (sc->sc_sysdev != NULL)
559 sc->sc_sysdev->hwmtx = NULL;
563 if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL)
564 (*sc->sc_sysdev->detach)(sc);
568 free(sc->sc_txbuf, M_UART);
569 free(sc->sc_rxbuf, M_UART);
571 if (sc->sc_ires != NULL) {
572 bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie);
573 bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid,
576 bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres);
578 mtx_destroy(&sc->sc_hwmtx_s);
580 if (sc->sc_class->size > sizeof(*sc)) {
581 device_set_softc(dev, NULL);
584 device_set_softc(dev, NULL);